No and Yes, it's not an app as in it's not available from the app stores (official or unofficial)... but when you save it as per the instructions it adds it to your app screen and it works very much in the same way as an app visually rather than a webpage. As you did ask for ideas, rather than re-inventing the wheel, and as others have mentioned I do believe you'd find it almost impossible to source the data, BSPL are not renowned for data sharing, if I were developing an app I'd be doing something interactive aimed at the kids, some along the lines of the old panini albums like fill a team screen with selfies with the riders, manager, mascot etc. add rewards and collectibles, make it addictive or something like the Pokemon app that swept the globe a few years ago, which was basically a treasure hunt. If you didn't have any success flogging it to the BSPL, the more forward thinking clubs that are trying to engage the kids with their interval kids races may be more receptive.

Thats up to the championship promoters and riders to sort out, not the PL promoters

No imo. If the PREM collapses then the CHAMP collapses too and clubs like Glasgow and Poole will have to open the cheque book anyway because current CHAMP HL's as well as British League D/UP's will demand much more money to cover a loss of income. It's a benefit to everyone for British Speedway to have 2 Main Tiers but 2 Main Tiers is only possible if powerhouse clubs are willing to put the Sport first instead of themselves. Unfortunately clubs don't operate like that over here, Hopefully one day they will but the Sport as a whole hasn't come first at an AGM in years.

Yes maybe possibly surely hopefully, any of these 

Better than sacrificing two well run like Poole & Glasgow to keep the PL going

Won’t be any of the above, close but not quite.